1. Field of the Invention
The invention relates to a method and an apparatus for automatically loading and unloading pieces goods of different shapes, dimensions, consistency and mass in a permanently installed conveying system.
Apparatus for picking up conveyed goods from permanently installed conveying devices are known as robots. Likewise, it is also known per se to deposit or to stack or store the conveyed goods at a position in the range of action of the robot.
For this purpose, on a freely moveable end of an arm belonging to the relevant robot, a corresponding pick-up device is fitted, for example a gripper. The pick-up device permits the conveyed goods to be picked up securely and reliably at their pick-up position and to be deposited again after being conveyed to their final position. For industrial applications, a very wide range of principles and embodiments for these pick-up devices are known. Inter alia, the following pick-up mechanisms are known. Mechanical gripping devices, which engage around the conveyed material, are used for example when loading sack-like conveyed goods. Vacuum grippers, that pick up the conveyed goods by suction, are used for example when loading conveyed goods similar to packages. Electromagnetic grippers for loading metallic conveyed goods are known.
The known load pick-up devices for robots all have the disadvantage that their respective pick-up principle is suitable only for a restricted bandwidth of conveyed goods. Therefore, in terms of their industrial application, these pick-up devices are restricted to specific conveyed goods. In particular, they cannot be employed in applications in which a large variety of conveyed goods have to be picked up and conveyed with the aid of the same pick-up device.
In addition, most of the known devices have the disadvantage that the conveyed material have to be enclosed by the pick-up device or covered from the side or from above in another form. This impairs the deposition of the conveyed goods to the extent that, for this purpose, corresponding movement clearances have to be reserved in the deposition area since, otherwise, the trouble-free removal and deposition are not ensured. If such clearances are not possible, depending on the location or the application, the corresponding pick-up mechanisms cannot be employed.
A prominent exemplary application, in which the disadvantages of the pick-up devices known nowadays come clearly to light, is the robot-assisted loading of pieces of baggage in airfreight containers. In this application it has to be possible to pick up securely a great physical variety of pieces of baggage, that is to say conveyed goods of different dimensions, consistency and mass.
In addition, these pieces of baggage have to be conveyed in a container that is accessible only from the side and have to be deposited there. Because of the movement space, which is severely restricted by the container walls and by pieces of baggage already present, of the robot with its pick-up device, pick-up devices known nowadays and belonging to the types previously described cannot be employed here.
It is accordingly an object of the invention to provide a method and an apparatus for automatically loading and unloading piece goods which overcome the above-mentioned disadvantages of the prior art devices and methods of this general type, such that the automatic loading and unloading of conveyed goods is now possible, irrespective of the shape, the dimensions, the consistency and the mass. In addition, the intention is to ensure that the conveyed goods are deposited at their target location in such a way that the apparatus itself reaches into the deposition area as little as possible.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for automatically loading and unloading piece goods of different shapes, consistencies and masses to/from a permanently installed conveying system. The method includes providing a remote controlled apparatus for automatically picking up the piece goods. The piece goods are gripped by friction by the remote controlled apparatus and are moved onto a pick-up platform of the remote controlled apparatus. The piece goods, after being picked up on the pick-up platform, are secured by force and/or shape against slipping off and falling down until the piece goods are unloaded. The piece goods are put down automatically by the remote controlled apparatus at an intended location.
According to the invention, the relevant piece goods are picked up automatically by a remote-controlled apparatus, by the piece goods being gripped by friction by the apparatus and moved onto a pick-up platform belonging to the apparatus. The piece goods, after being picked up on the pick-up platform, are then secured by force and/or shape against sliding off or falling down until they are unloaded, and are set down automatically by the apparatus at the intended location.
The loaded goods located on the relevant pick-up platform are advantageously secured by associated lateral bounding device(s), it being possible, in a further refinement of the invention, for the bounding devices to be adjusted to the relevant loaded goods.
An apparatus according to the invention for implementing the method previously described has, a robot with a carrying arm that can be moved along several axes and is formed from at least two-part arms. Disposed at the free end of the carrying arm is a conveyed-goods pick-up according to the invention, which has a pick-up platform which has a conveyor belt and is enclosed by a side wall on at least each of the two sides running transversely with respect to the conveying direction of the conveyor belt.
Described in simple terms, the apparatus according to the invention, which is fitted to the robot arm, is configured to be similar to a shovel, but the thrust movement usual in the case of a shovel to pick up the relevant conveyed goods does not occur here. Instead, the movement of the conveyor belt has the effect that the relevant conveyed goods to be picked up are continuously moved onto the pick-up platform, by the grippy conveyor belt gripping the conveyed material by friction and pulling it onto the pick-up platform until a limit switch or end stop provided there interrupts the conveying movement of the conveyor belt.
The invention therefore describes a device fixed to the robot arm to pick up conveyed goods. With the aid of this device, which is a translational conveyed-goods pick-up, conveyed goods can be picked up from permanently installed conveying devices, such as belt conveyors, and, using the robot, can be conveyed into a position located in the active range of the latter and deposited there.
A preferred area of use of the present invention is the loading and unloading of airfreight goods. The apparatus according to the invention is used in this case to pick up passenger baggage during the robot assisted loading of the baggage into-airfreight containers. However, the configuration described below is not restricted to this application but, if necessary with relatively small adaptations, can also be used for other loading processes.
According to a preferred embodiment of the invention, the conveyor belt is driven bidirectionally, an electric shaft motor preferably integrated into a deflection roller for the conveyor belt, which is constructed as an endless belt, being used as a drive.
In this case, it proves to be beneficial for the deflection rollers for the conveyor belt provided on the pick-up platform to have a diameter between 8% and 15% of the width of the conveyor belt, preferably 10%.
The conveyor belt is advantageously formed by a conveying belt whose surface has profiling which preferably runs transversely with respect to the conveying direction of the conveyor belt. Instead, for the purpose of improving the grippiness, the surface can also be provided with bumps, in order by this to effect the gripping of the relevant conveyed goods more reliably.
A further advantageous development of the invention provides for the conveyor belt to have, in each direction, a limit switch or end stop, which stops the forward and reverse run of the conveyor belt, respectively, as soon as the relevant conveyed goods have reached their final position on the pick-up platform or, respectively, left it.
The conveyor belt expediently has a thickness of at least 1 mm plus the profile height, so that the conveyor belt is also suitable for a small deflection radii.
With a view to simultaneously easy handling and a wide range of applications of the conveyed-goods pick-up, the length of the conveyor belt is at least 1.3 times its width, preferably 450 mm.
In order to secure the conveyed goods located on the pick-up platform adequately, the lateral side walls enclosing the pick-up platform are disposed such that they can be moved and, consequently, can be adapted to the dimension of the relevant conveyed goods.
In addition, the conveyed-goods pick-up according to the invention can be provided with at least one proximity sensor, which is expediently disposed on the pick-up platform and cooperates with a control device which, moreover, also performs the control of the basic appliance, that is to say the robot. As a supplement to this, a video monitoring system can also be provided, which monitors the operating sequence of the apparatus and co-operates with the control device.
According to a further advantageous refinement of the invention, the conveyed-goods pick-up according to the invention is disposed in an automatic conveying system for piece goods and performs the automatic loading and unloading of conveyed goods of different shapes, consistencies and mass into and from baggage trolleys which, for this purpose, are provided next to the conveying system.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method and an apparatus for automatically loading and unloading piece goods, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.